By Shari Vahl
BBC Radio 4
Simon and Christine Rowntree thought selling their large family house to move to a smaller property would be a simple process.
With their children grown up and the mortgage paid off, the couple picked a house round the corner from their home in Birmingham.
But there was one snag according to Land Registry, the body which records who owns land and property in England and Wales, the couple no longer owned the house they were selling.
"We couldn't believe it," said Christine, "We didn't have a mortgage on it, we owned it outright, it was just unbelievable."
"We felt physically sick. We had never experienced anything like this," added her husband Simon.
What the couple later discovered was that two people impersonating them had gone to a solicitor and instructed him to change the ownership of a house as they were giving it to a man they claimed was their son-in-law, a Mr Khalid.
The scam was simple. By doing a basic online search at Land Registry's website the criminal gang was able to find out the Rowntree's house had no mortgage.
Following the transfer of the title on the Land Register - this is how property ownership is recorded since title deeds were abolished in 2002 - the criminals mortgaged the Rowntree's house for £325,000.
The couple are not alone.
Thirty-six million pounds compensation has been paid out by Land Registry's indemnity fund for mistakes and fraud since 2005.
Police forces in England and Wales have told BBC File on 4 they are investigating a sharp rise in fraud where criminal gangs are able to obtain legal ownership of houses and property.
Det Insp Colin Radcliffe of Merseyside Police said it is possible for people to change a correspondence address with Land Registry without any proof of identity.
"It's possible for any man to go into Land Registry and say by filling in the correct forms, I now am the service address for that property, any correspondence from the LR can you send it to this new address," he said.
DI Radcliffe said once criminals have changed the service address of an empty property they might pose as a builder owed money by the person at this address and launch a civil action to reclaim the money.
If the court does not receive a reply from the person at the address it can order the house to be sold with the money going to the criminals.
In addition, if criminals then also pose as the property owner, and write to the court agreeing to home's sale, any money from the sale not owed to the criminals as claimants will also go to them.
Said DI Radcliffe, "We're looking at over a dozen cases and certainly on one, possibly more of those cases, this has happened and that property has been sold."
Land Registry promised action last May, on these kind of cases
but a BBC team was able to change the service address of a property in London without any checks made on their identity.
Matthew Wyles, Group Distribution Director of Nationwide Building Society, believes the availability of information about property ownership from Land Registry makes fraud easy and "root and branch" reform is needed.
"That's great big hole in the procedures, it is typical and indicative of the sort or risks inherent in the current open architecture, clearly Land Registry needs to go through all its procedures and challenge whether the procedures are as prudent as they should be," he said.
Land Registry maintains it has tightened its procedures. Last November it introduced new identity checks on everyone involved in buying or selling property.
But Julie Jenkins, head of fraud at Land Registry, admitted it did not require identity checks for changes of address.
"If we require identity checks when people are moving away there's often a speed needed to get the change on the register," she said.
"We need to ensure there's a balance between protecting the individual and protecting the property and that's what we're here to do.
Ms Jenkins added: "It's really important that people keep their contact addresses up to date."